Expandable assemblies



Sept. 25, 1962 EXPANDABLE AssEMB'LEs Filed May 19, 1961 '7 Sheets-Sheet l H. LUTz 3,055,463

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United States 'Patent 3,055,463 EXPANDABLE ASSEMBLIES Hermann Lutz, Hannover-Munden, Werrahaus, Germany, assignor to Rheinstahl Wanheim G.m.b.H., Duisburg-Wanheim, Germany Filed May 19, 1961, Ser. No. 111,400 i Claims priority, application Germany May 19, 1960 19 Claims. (Cl. 189-36) The present invention relates to expandable assemblies.

More particularly, the present invention relates to expandable assemblies which are used for locking relatively movable elements with respect to each other. For example, in mines there are pit props which support the roofs of the mine galleries. These pit props generally take the forms of telescope members one of which is axially movable relative to the other so that when expanded a pit prop will engage the floor and roof of the mine gallery, and because of the load which must be carried Iby such pit props it is necessary to provide a structure for locking the pit props in their roof-supporting positions so that the weight of the roof will not cause the roof to collapse.

Lock devices of the above type generally include wedge members which may be driven into a locking position by hammer blows, for example, but these arrangements are primitive and do not provide for uniform distribution of the load among a plurality of pit props, for example.

It is accordingly one of the primary objects of the present invention to provide an expandable assembly capable `of acting as a wedge to lock relatively movable elements in a predetermined position with respect to each other, and in accordance with the present invention the expandable assembly of the invention is capable of being expanded in a controlled precise manner which will enable, for example, uniform distribution of the load among a number of supporting elements such as pit props.

It is another object of the present invention to provide an expandable assembly o-f the above type which is capable of automatically retracting itself to its inoperative, rest position so that immediately upon release of the expandable assembly from the structure which it locks the expandable assembly is ready again for use and need not be placed by the operator in a predetermined condition to prepare it for -future use.

It is furthermore an object of the present invention to prevent an expandable assembly which is composed in its entirety of extremely simple rugged elements which will be capable of withstanding tremendous loads and which will also be capable of receiving hammer blows and the like without injury to the assembly.

An additional object of the present invent-ion is to provide a structure which can produce a considerable wedging or locking force without requiring the operator to expend a great deal of energy for this purpose.

With these objects in view, the invention includes in an expandable assembly an elongated outer hollow wedge means having .opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of the outer wedge means away from the interior thereof during expansion of this outer wedge means. An inner wedge means is located within the hollow outer wedge means and extends longitudinally thereof, and this inner wedge means also has opposed ends one of which is smaller .than the other. The smaller end of the inner wedge means is directed toward the smaller end of the outer wedge means and the inner wedge means has within the outer wedge means the rest position spaced from the smaller end of the outer wedge means. As the inner wedge means advances along the interior of the outer wedge means longitudinally toward the smaller end there- Patented Sept.'25, 1962 of, the inner wedge means will move the longitudinal wall portion of the outer wedge means away from the hollow interior thereof so as to expand the outer wedge means. A screw means is accessible at the exterior of the outer wedge means and cooperates with the inner wedge means to advance it toward the smaller end of the outer wedge means so as to expand the outer wedge means, and a spring means cooperates with the inner wedge means to urge it to its rest position within the outer wedge means.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation Itogether with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. l schematically represents the manner in which the expandable assembly of the invention may be used with a pit prop;

FIG. 2 is a schematic sectional elevation showing a simplified embodiment of an expandable assembly of the invention;

FIG. 3 is a longitudinal sectional elevation of another embodiment of an expandable assembly of the invention, the structure of FIG. 3 being shown in its operative posi- -tion just prior to expansion of the assembly so as to lock relatively movable elements with respect to each other;

FIG. 4 shows the structure of FIG. 3 after it has been expanded into a locking position;

FIG. 5 shows the structure of FIGS. 3 and 4 in its inoperative position prior to being placed in the position shown in FIG. 3;

FIG. 6 is a longitudinal sectional elevation of a further embodiment of an expandable assembly yaccording to the present invention, the assembly being shown in FIG. 6 in the operative position which it takes just prior to being expanded into a locking position;

FIG. 7 is a section taken along line VII-VII of FIG. 6;

FIG. 8 shows the position which the parts of FIG. 6 take after the structure has been expanded from the position of FIG. 6 into a locking position shown in FIG. 8; and

FIG. 9 shows the structure of FIGS. 6-8 in an inoperative rest position preparatory to being placed in the operative position shown in FIG. 6..

FIG. 1 illustrates diagrammatically how the expandable assembly of the invention is used in one application. There is shown in FIG. 1, in a schematic manner, a pit prop having a lower portion 1 which rests with its base 1a on the floor of the mine gallery. This elongated lower part 1 of the pit props slidably receives `in its interior the upper elongated pit prop element 2 which is telescopically movable within the outer element 1, so that through hydraulic fluid under pressure or the like, as is well known in the art, the part 2 may be elevated with respect to the part 1 so that the top or head portion 2a of the part 2 will engage and press algainst the roof of the mine gallery.

In order to releasably lock the pit prop elements 1 and 2 in their positions respectively engaging the floor and roof of the mine gallery, the outer member 1 fixedly carries at its top end portion a frame 3 which extends around but does not prevent axial movement of theupper portion 2 of the pit prop. The frame 3` has to the right of the elements 1 and 2, as viewed in FIG. l, a pair of spaced and mutually aligned U-shaped portions which receive the blocks 4 and 6. The block 6 of course engages the exterior surface of the inner or upper pit prop member 2, while the block 4 engages the outer curved ends of the pair of U-shaped portions of the frame 3, these blocks 4 and 6 extending between these portions.

In order to press the block 6 against the member 2 with a considerable force an expandable assembly is used, and in the conventional primitive practice which may still be found in some mines this element 5 is simply in the form of an elongated solid wedge member which is pounded into position between the blocks 4 and 6 with a hammer and which thus presses the block 6 against the element 2 so as to maintain the latter in its elevated position. Of course, this arrangement with a conventional one-piece wedge member 5 on the one hand requires a considerable amount of energy on the part of the operator and on the other hand cannot give any uniformity in the loading of the several pit props. In order to release the pit prop so that it can become contracted, the Wedge 5 is simply knocked out by the operator also with a hammer, the operator at this time applying the hammer to the smaller end of the wedge.

According to the present invention the expandable means or assembly 5, which usually extends horizontally during use, is composed essentially of a pair of units, namely, an outer hollow elongated wedge means and an inner wedge means located within the outer wedge means.

Referring to FIG. 2 where a simplied embodiment of the invention is illustrated, the expandable assembly of the invention shown in FIG. 2 includes the outer elongated hollow wedge means 11 and the inner wedge means 15 located therein. It will be noted that the outer wedge means 11 has opposed ends 13 and 14, the end 13 being smaller than the end 14, and the inner wedge means 15 also has opposed ends one of which is smaller than the other, and of course the smaller end of the wedge means 15 is directed to the smaller end 13 of the outer wedge means 11. The inner wedge means 15 is shown in FIG. 2 in a rest position which it takes where the smaller end of the inner wedge means 15 is spaced from the smaller end 13 of the outer wedge means 11, and during expansion of the outer wedge means the inner wedge means 15 advances longitudinally toward the smaller end of the outer wedge means 11. In order that it may be capable of expansion the outer wedge means 11 includes a longitudinal wall portion 12 which is laterally movable with respect to the remainder of the wedge means 11 toward and away from the interior of the latter. Of course, when at the longitudinal wall portion 12 of the outer wedge means 11 moves away from the hollow interior thereof, the outer wedge means 11 expands. It will be noted that the ends 13 and 14 overlap the ends of the longitudinal wall portion 12, so 4that while this wall portion 12 is free to move laterally it is restrained against longitudinal movement. The inclination of the outer surface 17 of the outer wedge means 11 is such that this exterior surface 17 is self-locking. In other words, in any plane which includes the axis of the assembly the exterior surface makes with this axis an extremely small angle so that when the outer wedge means is in its locking position and force which acts on the exterior surface 17 will have no tendency to shift the outer wedge means toward the right, as viewed in FIG. 2, to an unlocking position, and thus the structure is selflocking and will remain in the position in which it is placed by the operator.

In the interior of the hollow wedge means 11, the inner wedge means 15 is urged by a spring 19 to the right, as viewed in FIG. 2, toward the rest position of the inner wedge means 15 shown in FIG. 2, and the end 14 of the outer wedge means 11 threadedly carries a manually turnable screw 16 which bears at its left against the right end of the wedge means 15, so that the operator may turn the screw 16 and thus advance the wedge means 15 toward the smaller end 13 of the outer wedge means 11. Thus, element 16 forms a screw means accessible to the operator for advancing the wedge means 15 toward the smaller end of the outer wedge means, while the spring 19 constantly urges the inner wedge means 15 back toward its rest position. Although it may be possible to provide a surface 18 for the wedge means which is not self-locking, so that the spring 19 will readily return the element 15 to its rest position when permitted by the screw 16 and so that the inwardly directed force of the longitudinal wall portion 12 will urge the wedge means 15 to the right, as viewed in FIG. 2, in the structure shown in FIG. 2 there is applied to the surfaces 18 and 18a of the inner Wedge means 15 a lubricant Such as grease, for example, so as to maintain the frictional contact between the inner and outer wedge means at a minimum, and if desired, roller bearings may be provided between the inner and outer wedge means to maintain their frictional contact to a minimum. Thus, with the structure of the invention the inner wedge means encounters practically no resistance in its movement toward its rest position spaced from the smaller end of the outer wedge means.

It will be noted that the otuer wedge means forms a housing in which the inner wedge means is housed and protecting the inner wedge means from the exterior of the outer wedge means so that in this way the interior of the outer wedge means and the parts therein are protected from dirt and injury, and in the actual construction of a device as shown by diagrammatically in FIG. 2, the interior of the outer wedge means is in fact entirely closed off from the outer atmosphere.

It may be desirable in some cases to provide between the longitudinal wall portion 12 and the opposed wall of the outer wedge means 11 springs which urge the wall 12 toward the interior of the hollow wedge means, and of course in this case the movement of the wall 12 away from the interior of the outer wedge means by advancing of the inner wedge means 15 toward the wall 13 will take place in opposition to such laterally-acting springs.

The structure described and shown in FIG. 2 placed in the position of the element 5 shown in FIG. l. Thus, laterally movable wall portion 12 may be placed in engagement with the block 6, while the opposed part of the outer wedge means 11 will engage the block 4. The forces acting laterally on the wall 12 to urge the latter away from the interior of the outer wedge means, resulting from axial advancing of the inner wedge means 15 toward the wall 13, will be transferred to the block 6 and will press the latter against the pit prop element 2.

The assembly which is shown in FIG. 2 is originally introduced between the blocks 4 and 6 and the operator will with a few hammer blows on the end face 10 of the outer wedge means 11 drive the latter between the blocks 4 and 6 with a force sufficient to retain the expandable assembly of FIG. 2 in position between the blocks 4 and 6, but of course at this time the pressure of the block 6 against the member 2 is far less than required. In order to provide the necessary force for holding the element 2 in its elevated position the operator turns the screw 16 so as to advance the inner wedge means 15 toward the smaller end 13 of the outer wedge means, and because of the relatively low friction between the inner and outer wedge means and because of the direct engagement between the inner wedge means and the laterally movable wall portion 12 the latter is readily urged laterally away from the interior of the outer wedge means with a considerable force, even though the operator has not necessarily applied a very large force to turn the screw 16. It will be noted that the outer end of the screw 16 is located in a recess 20 which is formed in the end 14 of the outer wedge means 11 but does not extend outwardly beyond this recess 20 so that the screw 16 cannot be engaged by a hammer which is applied to the end `face 10 of the outer wedge means 11. Any suitable Wrench may be applied to the non-circular free end portion of the screw 16 which is accessible in the recess 20, and the wrench, which may be a suitable socket wrench, for example, may have a relatively long lever so that the operator can have a consider able mechanical advantage while moving the inner wedge means 15 toward the end 13 of the outer Wedge means 11.

Of course, the spring 19 during this movement is compressed and the wall 12 is urged in the direction of the arrow B shown in FIG. 1. Because of the relatively low friction at the surfaces 18 and 18a it is not necessary to apply a large force to the screw 16 for advancing the inner wedge means 15. Moreover, it is possible to provide a predetermined force on the block 6 by way of the expandable assembly of the invention and thus it becomes possible to provide the same clamping force on all of the pit props.

In order to remove the expandable assembly it may be knocked out by applying a hammer to the smaller end 13 of the outer wedge means 11, or the screw 16 may be retracted so that the spring 19 will return the inner wedge means 15 to its rest position and the longitudinal wall portion 12 of the outer wedge means can then move inwardly toward the interior of the outer wedge means 11.

The expandable assembly of the invention may have approximately the same outer dimensions as a conventional wedge which is used with the structure shown in FIG. 1 so that except for the expandable assembly of the invention all of the other parts are conventional, or, if desired, the expandable assembly of the invention may be of a somewhat larger size than a conventional wedge, and in this event the blocks 4 and 6 which are used with the expandable assembly of the invention may be made somewhat smaller than conventional so as to provide the necessary space for the larger expandable assembly of the invention.

Thus, it becomes possible to use the structure of the invention interchangeably with conventional structure in conventional assemblies for releasably locking devices similar to pit props, for example.

In accordance with the present invention, in order to avoid the necessity of turning the screw 16 back to its starting position, it is possible to arrange one-half of the nut which cooperates with the screw 16 on the part 12 and the other half on the remainder of the outer wedge means so that in this way a split nut is provided to form part of the screw means and when the expandable assembly is removed the split nut portions move away from each other to release the screw 16 for return to its starting position without requiring any turning of the screw 16 back to its starting position by the operator, and in this way the structure is immediately ready for reuse. In the rest position of the parts the sections of the nut are spaced from each other while when the parts are placed between the blocks 4 and 6 ready for operation the split nut portions engage each other to form a complete nut whose threads cooperate with the threads of the screw 16. With such an arrangement, as soon as the expandable assembly is knocked out of the space between the blocks 4 and 6 springs or the like urge the split nut portions away from each other and so that the screw is immediately released and returned through a suitable means such as the springs 19 back to its starting position, and of course the inner wedge means 15 will also return to its starting position immediately with such a construction. With such an arrangement any suitable means may be provided to maintain the screw 16 at all times engaged with the wedge means 15.

In the embodiments of the invention which are described below there are such split nut assemblies which cooperate with and form part of the screw means so that when the expandable assemblies described below are removed from their locking positions the parts will immediately return to a rest position ready for use.

In the embodiment of FIGS. 3-5, the elongated hollow outer wedge means 101 is composed of a pair of elongated portions 101a and 101b which are complementary to and substantially mirror images of each other and which cooperate together to define the elongated hollow interior space of the outer wedge means 101. These elongated longitudinal portions 101a and 101b respectively have exterior inclined surfaces 101C which are self-locking. The outer wedge means 101 ha-s a relatively large end 101d and op- 6 posed relatively small end 101e, and by applying a hammer to the larger end 101:1 it is possible to place the assembly in its operative position shown in FIG. 3 between, for example, a pair of blocks `such as the blocks 4 and 6 of FIG. l. The assembly is removed from the blocks or `the like by applying the hammer to the smaller end 101e of the outer wedge means, so that in this way the parts will again return to their rest position.

Within the outer hollow elongated wedge means 101 is located an inner wedge means 102 which extends longitudinally of the outer wedge means 101 and which also has opposed ends one of which is smaller than the other. It will be noted that the smaller end of the inner wedge means `102 is directed toward the smaller end 101e of the outer wedge means 101. This inner wedge means 102 is in the form of a solid block of metal having substantially the configuration indicated in FIG. 3. The spreading of the portions 101e and 101b of the outer wedge means away from each other in `the directions indicated by the arrows B in FIG. 3 takes place by advance of the inner wedge means 102 in the direction of the arrow A of FIG. 3 toward the smaller end 101e of the outer wedge means 101. The inclination of the exterior surface of the inner wedge means 102 corresponds to that of Ithe outer wedge means so that the surfaces 102a are also self-locking. These surfaces 102a slide along the inner surfaces of the outer wedge means -101 which inner surfaces have the same inclination as the sur-faces 102:1. The friction between the outer surfaces 102a of the inner wedge means and the inner surfaces of the outer wedge means is maintained relatively low by lubrication or by arrangement of unillustrated roller bearings or the like at the surfaces. This frictional engagement between the inner and outer wedge means is substantially less than the frictional engagement between the exterior surfaces 101C of the outer wedge means and elements such as the blocks 4 and 6. The entire inner free space of the outer wedge means of FIG. 3 may be lled with a lubricant such as grease or the like, so that in this way not only are the relatively movable parts lubricated, but in addition dust 4and other foreign matter is kept away from the interior of the outer wedge means.

The advancing `of the inner wedge means 102 toward the smaller end of the outer wedge means 101 is brought about by way of'manually operable screw means which includes the elongated screw member 103 which extends longitudinally along part of the interior of the outer wedge means and which has a non-circular free end portion 103e which is freely accessible at the exterior of the outer wedge means so that a suitable wrench may 'be :applied to the screw member 103 so as to turn the latter. The screw member |103 has an elongated portion 10311 which is threaded and next to this elongated portion 103a an elongated portion 103b which has no threads. The Unthreaded portion 10312 extends into a recess 105 formed in the larger end of the inner wedge means 102, and the screw 103 is xed to a collar 104 which is also located in the recess 105. While the screw member 103 and the collar 104 have a certain axial play within the recess- 105, the top end portion of the wedge means 102, as viewed in FIG. 3 overlaps the collar 104 so as to prevent removal of the collar 104 'and the part of -the screw 103 fixed thereto from the recess 105. A spring 106 engages the lower end of the recess 105, as viewed in FIG. 3, and the collar 104 so as to urge the screw member 103 to the position illustrated in FIG. 3. It will lbe noted that in this position the screw member 103 and the collar 104 are movable in opposition to the screw `106 toward the smaller end of the inner wedge means.

A split nut means 108 which has a pair of nut halves 108:1 and 10817 cooperates with the screw member l103 and forms part of the screw means for advancing the inner wedge means 102. The sections 108e: and 108]:

of the split nut 108 surround the screw 103. The portions 101a and 101b of the outer wedge means are respectively provided in the interior of the outer wedge means 101 with a pair of elongated oppositely inclined Wall portions 109 which are integral with the sections 10111 and 101b, and it will be noted that these wall portions 109 converge toward the larger end 101b of the outer wedge means. The nut sections 10811 and 108b are respectively in slidable engagement with the wall portions 109, and these wall portions 109 may, for example, respectively have elongated ribs located slidably in grooves at the exterior of the nut sections 10811 and 108b, these ribs and grooves extending longitudinally of the wedge means so that in this way while the split nut means 108 is capable of moving axially it cannot rotate with respect to the outer wedge means. It will be noted that the inclination of the wall portions 109 is opposed to the inclination of the surfaces 101e.

Just below the wall portions 109, as viewed in FIG. 3, the portions 10111 and 101b of the outer wedge means have transversely extending wall portions respectively formed with openings through which a pair of coil springs 110 freely pass. These coil springs are connected at one end in any suitable way to the sections 10811 and 108b of the split nut means as well as to the inner wedge means 102, 'as shown at 107, for example, so that these springs 110 urge the split nut means and the inner wedge means to the position shown in FIG. 3 where these elements engage the opposed faces of these transverse wall portions of the outer wedge means 101. Thus, the wall portions 111 which are respectively formed with the bores through which the springs 1110 freely pass serve aS stop elements determining the rest positions of the inner wedge means 102 and the split nut means 103.

A limiting means is provided to limit the outward movement or spreading apart of the portions 10111 and 101b of the outer wedge means 101, and the limiting means in the example shown in FIG. 3 takes the form of a plate 112 formed with an opening through which the screw 103 freely passes and having an upwardly directed, as viewed in FIG. 3, annular flange 113 which forms a ring surrounding projections 114 of the sections 10111 and 101b of the outer wedge means 101. These projections 114 may be arcuate and are received within the space surrounded by the flange or ring 113. Springs 115 respectively engage the upper ends of the walls 109 and are fixed thereto in any suitable way, and these springs are also fixed to and push against the element 112 so as to urge the latter toward the large end 101d of the outer wedge means, and in this way the ring or flange 113 is maintained at all times surrounding the projections 114 to engage these projections and thus limit the spreading apart of the portions 10111 and 101b in directions indicated by the arrows B in FIG. 3.

A similar arrangement is provided at the smaller end 101e, and as is shown at the lower portion of FIG. 3 a plate 11211 is provided with a ange 11311 surrounding projections 11411 at the smaller ends of the sections 10111 and 10111 of the outer wedge means, and the plate 11211 is lixed by a screw member to a collar located at the exterior of the wedge means in the recess at the smaller end 101e thereof so that in this way the element 11211 is maintained in the position shown in FIG. 3 where the ange or ring 11311- surrounds at all times the projections 11411.

It will be noted that the non-circular wrench-receiving end 103C of the screw member 1103 is located in a recess i116 Aformed by the portions `10111 and 10111 of the outer wedge means and does not extend beyond the larger end 101b of the outer wedge means so that in this way when a hammer is applied to the larger end of the wedge means the screw member 103 will not be ienfggaged by the harnmer, but at the same time it is `freely accessible to a socket wrench or the iike. The turning of the screw member 103 will result in advancing of the inner wedge means i102 in the direction of the arrow A, and instead of a handeoperated wrench it is also possible to lapply to the end 103C of the screw 103 a motor-driven wrench.

rPhe structure 4is shown in FIG. 3 in the position ift takes when it has bee-n placed between a pair of elements such as the blocks 4 and 6 of FIG. l for application of a hammer to the end 101111 so that the sections 10111 and 10111 of the outer wedge means 101 are maintained by the blocks 4 and 6 relatively close to each other, and it will be noted that in this position of the parts the sections 10311 and 10811 of the split nut 108 engage each other to form a Icomplete nut. In this position, however, inner wedge means 102 has not yet been advanced toward the smaller end 101e of the outer wedge means. Moreover, it will be noted that the threaded portions 10311 has not yet been :advanced into engagement with the threads of lthe nut `108. Thus, the knocking of the expandable `assembly into the space between the element such as the blocks 4 and 6 of FlG. l will only move the parts laterally ltoward `each other but will not result in 'advancing of the inner wedge means 102.

In order to advance the inner wedge means 102 toward fthe smaller end of the outer wedge means, the operator pushes the screw 103 by the wrench `which is applied to the end 103e thereof Kfor turning the same in the direction of the `arrow A against the force of the spring i106 toward the smaller end of the outer wedge means, and this will place the end of the threaded portion `10311 in engagement with the inner threads of the nut 10S.

When the screw member 103 is pushed in lthe direction of the arrow A in opposition to the spring 106 so as to place the threaded pontion 10311 in engagement with the end of the nut 108, the portion 103]; of the screw member which extends ydownwardly beyond the collar 104+, as viewed in vFIG. 3 stil-l `does not engage the inner wedge means 102, and in Iaddition the collar 104- is still out of engagement with the annular surface `10511 of the recess 105, this surface 10511 being directed upwardly, as viewed in FIG. 3. Thus, the initial turning of the screw member 1103 will not result in yadvance of the inner wedge means `102 and will only result in turning of the threads of lthe screw member into `the threads of the nut 108, so that several of the threads of the nut 108 are engaged by the threads of the screw 103 before the collar 104 engages the surface 10511. Therefore, the axial force which advances the inner wedge means 102 is not applied to the iatter until the screw member is in secure -threaded engagement with the 4nuit 103, land in -this way injury to the threads as a result of the force applied thereto is reliably avoided.

After the collar 104 engages the surface 110511, the continued turning of the screw member 103 will advance the inner wedge means 102 toward the smaller end of the outer wedge means, :and this advancing of lthe inner wedgc means will take place, yfor example, until 4the parts have the position shown in FIG. 4, and in this position the sections 10111 and 101111 of the louter wedge means 101 are urged apart from each other with la considerable force providing the desired frictional engagement between elements such las the block 6 and the member 2 of the pit prop. It will be noted from FIG. 4 that in addition to advancing of the inner wedge means 102, the split nut (108 has also been moved to some extent along the inclined wall portion 109, land of course the springs 110 are under considerable tension as compared to their condition in the operative position of the expandable assembly shown in FIG. 3. As is apparent from FIG. 4, the ad- Vance of the inner wedge means 102 has resulted in spreading apart of the portions 10111 and 101b of the 'outer wedge means 1011 in the direction of the arrows B shown in FIG. 4. 'Ille movement of the nut 103 in the direction indicated 1by the upwardly `directed arrow of FIG. 4 takes place without turning of the nut |108.

As is well known, fthe wrench which is applied to the end 103e of the screw 'member 103 or the motor which s 9- u'sed for this purpose may -tbe operatively connected with a meter which will indicate the 'force Iapplied to the screw member, Kand in :this way fthe lclamping force provided by fthe expandable assembly can be predetermined. The clamping torce of ycourse acts substantially perpendicularlly to the iongitudin-al axis of the expandable assembly.

FIG. shows the embodiment of FIGS. 3 and 4 in the position it takes whe-n the parts thereof are .at rest, which is to say preparatory to being placed in Ithe position shown in FIG. 3 between a pair of elements such as the blocks 4 and 6 of FIG. 1. The parts immediately move to the rest position shown in FIG. 5 when knocked out oi the locking position between rb-loclas such as the elements 4 and 6. As soon as the expandable assembly is removed from its position between elements such as Ithe blocks 4 and 6, the sections or portions loda and 101.5 of fthe outer wedge means i101 are free to move apart from yeach other in the direction of the arrows B shown in FIG. 5, and this movement of these portions of the outer Wedges means 'away trom each other may be provided, if desired, by spring means which is unillustr-ated and Iwhich is [located Within the outer wedge means constantly urging the sections Mila, 10111) thereof apart trom each other. This movement of the portions 10101 and 1Mb apart iro-m each other automaticalily separates the sections 1i8a :and l0-8b of the split nut 103 trom each other so that the screw `103 4is immediately released from the nut 16S and the yspring 1106 `can immediately return the screw :103 to the position where the collar 104 engages the portions 107 of the inner wedge means i102 which overlap the col-lar 104, las indicated FIG. 5. Moreover, the springs i110 immediately contract so as to reto-nn the split nut means S :and the inner wedge means 102 to the position indicated in FIG. 5 engaging the opposed yfaces of the [transverse wall portion-s i111. Thus, with this arrangement it i-s unnecessary for the operator to return their par-ts to 'their rest positions, these parts returning automatically and immediately to the position :indicated in FIG. 5 where fthe entire assembly is again ready -for use. It will be noted that in this position the projections 114 engage the ring i113 and the projections 114e engage the ring 113m so that, as `described above, the outward movement of the parts 1010i and 1Mb from ieach other i-s Ilimi-ted.

In the embodiment of the invention which is illustrated in FIGS. 6 9, the structure of the outer wedge means is considerably different from that of FIGS. 3-5. This outer wedge means of FIGS. 6-9 includes a one-piece hollow housing 118 having the opposed ends 118a and 111th adapted to be engaged by a hammer, the end llb being substantially smaller than the end 118e` oi the outer wedge means. The hollow elongated housing 118 is formed in a pair of its opposed side walls with elongated cutouts into which extend portions of a pair of longitudinally extending movable wall portions 119 of the outer wedge means, these longitudinal wall portions 119 of the outer wedge means being laterally movable toward and away from the hollow interior of the outer wedge means. It will be noted that the cooperation of the wall portions 119 with the one-piece housing member 118 is such that these wall portions 119` cannot move longitudinally of the outer wedge means but `are free to move laterally. These longitudinal wall portions 119 directly engage elements such as the blocks 4 and 6, `and for this purpose these wall portions 119 have the self-locking surfaces 11911 and 119b, respectively.

Also, in the embodiment of FIGS. 6-9, the inner wedge means is longitudinally split and formed of a pair of longitudinal portions 121161 and 120E, these portions of the inner wedge means 120' being located in the hollow interior of the outer wedge means, in the housing 118 thereof and being longitudinally movable within this housing. It will be noted from FIG. 6 that the smaller end of the inner wedge means 120 is directed to the smaller end 11817 of the outer wedge means, while the inner wedge means has a larger end directed toward the larger end 11861 of the outer wedge means, and in the operative position of the parts shown in FIG. 6 which is the position where the expandable assembly has been just placed between the blocks 4E and 6 preparatory to advancing the inner wedge means toward the smaller end of the outer wedge means, this inner wedge means 120 is spaced considerably from the smaller end 118b of the outer wedge means. The embodiment of FIGS. 6-9 also includes a split nut means, and in this embodiment the split nut 121 includes the sections 121e and 121b which are respectively ixed rto the sections 121m and 12% of the inner wedge means, as by being formed integrally therewith, and it will be noted from FIG. 6 that the sections of the split nut 121 are located at the larger end of the inner wedge means 120. The inner wedge means 126 has exterior inclined surface portions 120e respectively engaging, under reduced friction provided by lubrication, for example, the inner surfaces 119a' of the longitudinal wall portions 119 of the outer wedge means. The friction of the embodiment of FIGS. 6-9 may also be maintained at a minimum yby a suitable lubricant such as grease or the like in the interior of the outer wedge means, and the inclination of the surfaces 120e which engage the surfaces 1194i of the longitudinal wall portions 119 have the same inclination as the surfaces 11951'. As is shown most clearly in FIG. 7, the elongated housing 118 has in its interior a pair of longitudinally extending guide ribs 117 and 117a, and these guide ribs extend between corresponding ribs of the portions 12Go and 121th of the inner wedge means to limit the movement of these portions toward the central longitudinal axis of the entire assembly, and in this way the separate portions of the inner wedge means are maintained in alignment with the longitudinal axis of the entire assembly and prevent any misalignment between the screw mem-ber 122 and the inner wedge means.

The elongated screw member 122 extends along the interior of the outer wedge means and between the portions 12tla and 120i; of the inner wedge means 129. This screw member 120 has an elongated threaded portion 122e, and directly next to this threaded portion the screw member 122 has an Unthreaded portion 1225 located between the nut sections 12111 Vand 121b in the position of the parts shown in FIG. 6. The unthreaded end portion 122b of the screw member 122 extends into a recess 118e formed in the inner end of the housing 118 at its larger end 118a. A coil spring 123 surrounds a portion of the screw member 122 and engages at one end a collar 124 rwhich is iixed to the screw member 122. The coil spring 123 engages at its other end a washer 125 with respect to which the screw member 122 is freely movable in an axial direction, this washer 125 surrounding the screw member 122, as indicated in FIG. 6. The washer 12S is urged by the spring 123 against the upper ends, and as viewed in FIG. 6, of the portions 12th: and 120b of the inner wedge means 120. The non-circular free end 122C of the screw member 122 is accessible at the exterior of the outer wedge means and is located in a recess 118:11 formed in the member 118, and it will be noted that the screw member, in the position of the parts shown in FIG. 6, does not extend outwardly beyond the end 118b of the housing 118, so that the screw member can never be engaged by a hammer while at the same time it is freely accessible to a wrench which maybe either manually or motor operated, as described above. An endless resilient sealing member 126 of soft rubber or the like is fixed to each of the members 119 along its periphery and engages the housing 118 surrounding the opening thereof through which the particular member 119 extends, so that in this way the interior of the housing 118 is closed off from the outer atmosphere and dust or foreign matter cannot reach the elements in the interior of the expandable assembly of FIGS. 6-9. Furthermore, these compressible resilient sealing rings 126 urge the longitudinal portions 119 of the outer wedge means laterally away from the hollow 1 1 interior of the outer wedge means in the directions of the arrows B shown in FIG. 6.

As is most clearly shown in FIG. 7, the longitudinal wall portions 119 are formed with grooves 119e which receive longitudinal flanges of the portions 120a and 129k of the inner wedge means so that while the inner wedge means is longitudinally movable with respect to the wall portions 119, when these wall portions 119 move outwardly away from the hollow interior of the outer wedge means they will also move the portions 12011 and 1201 of the inner wedge means apart from each other, and of course the split nut sections 121a and 121b will move apart from each other together with the inner wedge means sections or portions 120a and 120]).

As is shown at the lower portion of FIG. 6, the bottom face as viewed in FIG. 6, 118e of the recess 113e forms the abutment which is engaged by the screw member 122 during turning thereof to limit the axial advance of the screw member and thus guarantee axial advancing of the inner wedge means 120 during turning of the screw member.

FIG. 6 shows the position of the assembly after it has been introduced between elements such as the blocks 4 and 6 of FIG. 1 so that the assembly is now in its operative position preparatory to turning of the screw member 122 and advancing thereof so as to move the inner wedge means toward the smaller end of the outer wedge means. The parts are placed in the position shown in FIG. 6 by application, for example, of a hammer against the larger end 118a of the outer wedge means of FIGS. 6 9. In order to provide the desired clamping force the operator applies a wrench or the like to the end 122e of the screw member 122, and it will be noted that in the position of the parts shown in FIG. 6 the threaded portion 122g has not yet engaged the nut 121 whose sections 121a and 121!) have been moved into engagement with each other when the parts are in the position shown in FIG. 6. The operator when engaging the screw member 122 with a wrench or the like advances the screw member in opposition to the spring 123 downwardly, as viewed in FIG. 6, and as shown by the lower arrow of FIG. 6, and this will place the lower end of the threaded portion 122e as viewed in FIG. 6, in engagement with the threads of the nut 121. The bottom end of the screw member, as viewed in FIG. 6, has not yet reached the surface 113e. It is only during subsequent turning of the screw member 122. after some of the threads thereof have fully engaged the threads of the nut 121 that the free end of the screw member 122 engages the surface 118e, so that in this way the axial advancing of the inner wedge means 12) cannot take place until there is a secure engagement between the threads of the screw member and split nut means, and in this way damaging of the threads is reliably avoided. After the free end of the screw member 122 has engaged the abutment surface 118e, the continued turning of the screw member 122 will advance the inner wedge means 120 upwardly, as shown by the upwardly directed arrow cf FIG. 6, and this will result in outward movement of the longitudinal wall portions 119 or the outer wedge means in the directions indicated by the arrows B of FIG. 6, so that at this time the clamping force provided by the expandable assembly is increasing, and the turning of the screw is continued by `the operator until the desired amount of force is provided, as is indicated by a suitable meter, for example. lOf course, during the advancing of the inner wedge means 120 toward the smaller member 11811 of the outer wedge means, the spring 123 is constantly compressed to an increasing degree.

FIG. 8 illustrates the positions of the parts when they are in a locking position providing the desired amount of force in an assembly such as that shown in FIG. l, and it will be noted that in this position of the parts the screw member 122 engages the bottom of the recess 118e, the spring 123 is compressed, and the inner wedge means 12()` has advanced toward the smaller end 11Sb from the position indicated in FIG. 6, thus forcing the wall portions 119 outwardly away from the hollow interior of the outer wedge means. The parts will remain in the position shown in FIG. 8 until it is desired to release the structure holding elements such as the elements 1 and 2 in their operative position.

In order to remove the expandable assembly of the invention from its position between elements such as the blocks 4 and 6 of FIG. l, a hammer is applied to the smaller end 11811 of the outer wedge means, and as soon as the expandable assembly is knocked out of its position between the blocks the springy sealing rings 126 are capable of expanding to the position indicated in FIG. 9 so that they immediately withdraw the longitudinal wall portions 119 outwardly away from the interior of the outer wedge means. Because of the cooperation of the flanges of the inner wedge means 120 with the grooves 119C, the sections 120a and 12011 of the inner wedge means will also move apart from each other, together with the wall portions 119, to the position indicated in FIG. 9, and as a result the split nut 121 will have its sections 121a and 121b also moving apart from each other to the position indicated in FIG. 9, so that immediately upon movement of the expandable assembly out of the space between elements such as the blocks 4 and 6 the inner wedge means and the split nut means expand so as to immediately release the screw member 122 which is immediately moved by the spring 123 to the position indicated in FIG. 9 where the collar 124 engages a transverse face of the housing 118 to limit the movement of the screw 122 by the spring 123. At the same time, the expansion of the spring 123 acts through the washer 125 on the portions 12in and 1201; of the inner wedge means to urge these portions back toward the larger end 118.1 of the outer wedge means so as to immediately place the inner wedge means in its rest position, and in this way the structure is immediately ready for reuse. FIG. 9, cf course, show the parts in their rest position preparatory to being placed between a pair of elements such as the blocks 4 and 6 by application of a hammer to the end 113:1 of the expandable assembly, and when thus placed between such blocks the parts will have the position shown in FIG. 6 which is the operative position preparatory to turning and advancing of the `screw 122 so as to place the parts in the position shown in FIG. 8.

The inclination of the wedging surfaces of the expandable assembly is such that a considerable mechanical advantage is obtained and it is possible to provide extremely high clamping forces when applying to the screw members of the assemblies of the invention forces well within the capabilities of the average person. As may be seen from a comparison of the embodiment in FIGS. 3-5 with that of FIGS. 6-9, the non-circular free end of the screw member which is engaged by the operator may be located either at the larger end of the outer wedge means, as shown in FIGS. 3-5, or at the smaller end of the outer wedge means, as shown in FIGS. 6, 8 and 9.

If desired, suitable indicators may be provided to indicate at the exterior of the expandable assembly the extent of `force provided thereby. For example, any suitable indicator may indicate the extent of longitudinal advance of the inner wedge means so as to indicate in this way the extent to which the expandable assembly has been expanded to provide a predetermined clamping force. In this way it is possible to control several pit props, for example, so that they are uniformly clamped.

Of course, variations are possible within the scope of the invention. For example, it is possible in the embodiment of FIGS. 6-9 to have only one longitudinal wall portion 119 laterally movable toward and away from the hollow interior of the outer wedge means, as is the case with the embodiment of FIG. 2. With such an arrangement it is only necessary to support the screw member 122 properly at the side of the outer wedge means which i's opposed to that side where the laterally movable wall portion 119 is located, and such an arrangement does not change the principle of operation of the expandable assembly of the invention. lt merely results in a simpliiication of the structure and in a reduction in the volume of space occupied thereby.

lt will be understood that each of the elements described above or two or more together, may also find a useful application in other types of expandable assemblies differing from the types described above.

While the invention has been illustrated and described as embodied in expandable wedge assemblies, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

l. An expandable assembly comprising, in combination, an outer elongated hollow wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of said outer hollow wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward the smaller end of said outer wedge means and the larger end of said inner wedge means being directed toward the larger end of said outer wedge means, said inner wedge means having a rest position in said outer wedge means spaced from said smaller end thereof and being longitudinally movable within said outer wedge means toward said smaller end thereof for laterally displacing said longitudinal wall portion of said outer wedge means to expand the latter; and screw means accessible at the exterior of said outer wedge means, extending longitudinally along at least part of the interior thereof, and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand said outer wedge means.

2. An expandable assembly comprising, in combination, an outer elongated hollow wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of said outer hollow wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward the smaller end of said outer wedge means and the larger end of said inner wedge means being directed toward the larger end of sai-d outer wedge means, said inner wedge means having a rest position in said outer wedge means spaced from said smaller end thereof and being longitudinally movable within said outer wedge means toward said smaller end thereof for laterally displacing said longitudinal wall portion of said outer wedge means to expand the latter; screw means accessible at the exterior of said outer wedge means, extending longitudinally along at least part yof the interior thereof, and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand said outer wedge means; and spring means cooperating with la said inner wedge means for urging the latter from said smaller end of said outer wedge means toward said rest position of said inner wedge means.

3. An expandable assembly comprising, in combination, an outer elongated hollow wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of said outer hollow wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward the smaller end of said outer wedge means and the larger end of said inner wedge means being directed toward the larger end of said outer wedge means, said inner wedge means having la rest position in said outer wedge means spaced from said smaller end thereof and being longitudinally mov- `able within said outer wedge means toward said smaller end thereof for laterally displacing said longitudinal wall portion of said outer wedge means to expand the latter; and screw means accessible at the exterior of said outer wedge means, extending longitudinally along at least part of the interior thereof, and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand said outer wedge means; and spring means cooperating with said screw means for urging the same to Ia rest position.

4. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable with respect to the remainder of said hollow outer wedge means; inner wedge means extending longitudinally of and located within said outer wedge means, said inner wedge means having also opposed ends one of which is smaller than the other and said smaller end of said inner Wedge means being directed toward said smaller end of said outer wedge means, said inner wedge means having a larger end directed toward the larger end of said outer wedge means; an elongated screw member extending longitudinally of said outer wedge means at least partly along the interior thereof and being accessible at the exterior of said outer wedge means; and split nut means located within said outer wedge means and having a rest position spaced from said screw member and an operative position closely surrounding said screw member to cooperate therewith, said screw member cooperating with one of said wedge means and said split nut means cooperating with the other of said wedge means for advancing said inner wedge means from a rest position spaced from said smaller end of said outer wedge means longitudinally of the latter toward said smaller end thereof to laterally move said longitudinal wall portion of said outer wedge means away from the hollow interior thereof to expand said outer wedge means.

5. An expandable assembly comprising, in combina tion, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable with respect to the remainder of said hollow outer wedge means; inner wedge means extending longitudinally of and located within said outer wedge means, said inner wedge means having also opposed ends one of which is smaller than the other and said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means, said inner wedge means having a larger end -directed toward the larger end of said outer wedge means; an elongated screw member extending longitudinally of said outer wedge means at least partly along the interior thereof and being accessible at the exterior of said outer wedge means; split nut means located within said outer wedge means and having a rest position spaced from said screw member and an operative position closely surrounding said screw member to cooperate therewith, said screw member cooperating with one of said wedge means and said split nut means cooperating with the other of said wedge means for advancing said inner wedge means from a rest position spaced from said smaller end of said outer wedge means longitudinally of the latter toward said smaller end thereof to laterally move said longitudinal wall portion of said outer wedge means away from the hollow interior thereof to expand said outer wedge means; and spring means cooperating with said split nut means for urging the latter to said rest position thereof.

6. An expandable assembly comprising, in combination, an elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable with respect to the remainder of said elongated hollow outer wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner and outer wedge means respectively having their larger ends directed toward each other, said inner wedge means having a rest position spaced from said smaller end of said outer wedge means and being movable longitudinally of said outer wedge means toward said smaller end thereof for displacing said longitudinal Wall portion laterally away from the interior of said outer wedge means to expand the latter; an elongated screw member extending longitudinally of said outer wedge means at least partly along the interior thereof and being accessible at the exterior of said outer wedge means; nut means located in the interior of said outer wedge means and cooperating with said screw member during turning of the latter, said screw member cooperating with one of said wedge means and said nut means cooperating with the other of said Wedge means for advancing said inner wedge means toward said smaller end of said outer wedge means during turning of said screw member to expand said outer wedge means, that one of said wedge means with which said screw member cooperates including an abutment limiting the axial movement of said screw member with respect to the wedge means with which it cooperates only after at least some of the threads of said screw member are in threaded engagement with said nut means, said screw member having a rest position when none of the threads thereof are in engagement with said nut means.

7. An expandable assembly comprising, in combination, an elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable with respect to the remainder of said elongated hollow outer wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner and outer wedge means respectively having their larger ends directed toward each other, said inner wedge means having a rest position spaced from said smaller end of said outer wedge means and being movable longitudinally of said outer wedge means toward said smaller end thereof for displacing said longitudinal wall portion laterally away from the interior of said outer wedge means to expand the latter; an elongated screw member extending longitudinally of said outer wedge means at least partly along the interior thereof and being accessible at the exterior of said outer wedge means; nut means located in the interior of said outer wedge means and cooperating with said screw member during turning of the latter, said screw member cooperating with one of said wedge means and said nut means cooperating with the other of said wedge means for advancing said inner wedge means toward said smaller end of said outer wedge means during turning of 'i5 said screw member to expand said outer wedge means, that one of said wedge means with which said screw member cooperates including an abutment limiting the axial movement of said screw member with respect to the wedge means with which it cooperates only after at least some of the threads of said screw member are in threaded engagement with said nut means, said screw member having a rest position when none of the threads thereof are in engagement with said nut means; and spring means cooperating with said screw member for urging the same to said rest position when none of said threads thereof are in engagement with said nut means.

8. An expandable assembly comprising, in combination, an outer elongated hollow wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of saidv outer hollow wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward the smaller end of said outer wedge means and the larger end of said inner wedge means being directed toward the larger end of said outer wedge means, said inner wedge means having a rest position in said outer wedge means spaced from said smaller end thereof and being longitudinally movable Within said outer wedge means toward said smaller end thereof for laterally displacing said longitudinal wall portion of said outer wedge means to expand the latter; and screw means accessible at the exterior of said outer wedge means at one of the ends thereof, extending longitudinally along at least part of the interior thereof, and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand said outer wedge means.

9. An expandable assembly comprising, in combination, elongated outer hollow wedge means including a pair of elongated separate portions extending longitudinally of said outer wedge means and being laterally movable with respect to each other, said outer wedge means having opposed ends one of which is smaller than the other and said pair of longitudinal portions having in the interior of said outer wedge means a pair of opposed wall portions, respectively, which converge toward the larger end of said outer wedge means; a split nut in said outer wedge means between said converging wall portions thereof and having a pair of separate sections respectively engaging said wall portions so that as said sections advance toward said larger end of said wedge means said sections are pressed toward each other and engage each other; an elongated screw member extending longitudinally along said outer wedge means partly in the interior thereof and being accessible at the exterior of said outer wedge means, said screw member cooperating with said split nut means for urging the same toward said larger end of said outer wedge means; and inner wedge means located within and extending longitudinally along said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means having a rest position within said outer wedge means spaced from said smaller end thereof, said inner wedge means being longitudinally movable toward said smaller end of said outer wedge means for spreading said longitudinal portions thereof laterally apart from each other, said screw member cooperating with said inner wedge means for advancing the same toward said smaller end of said outer wedge means.

10. An expandable assembly comprising, in combination, elongated outer hollow wedge means including a pair of elongated separate portions extending longitudinally `of said outer wedge means and being laterally movable with respect to each other, said outer wedge means having opposed ends one of which is smaller than the other and said pair of longitudinal portions having in the interior of said outer wedge means a pair of opposed Wall por-tions, respectively, which converge toward the larger end of said outer wedge means; la split nut in said outer wedge means between said converging wall portions thereof and having a pair of separate sections respectively engaging said wall portions so that as said sections advance toward said larger end of said wedge means said sections are pressed toward each other and engage each other; an elongated screw member extending longitudinally along said outer wedge means partly in the interior thereof and being accessible at the exterior of said outer wedge means, said screw member cooperating with said split nut means for urging the same toward said larger end of said outer wedge means; inner wedge means located within and extending longitudinally along said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means having a rest position within said outer wedge means spaced from said smaller end thereof, said inner wedge means being longitudinally movable toward said smaller end of said outer wedge means for spreading said longitudinal portions thereof laterally apart from each other, said screw member cooperating with said inner wedge means for advancing the same toward said smaller end of said outer wedge means; and spring means connected to the sections of said split nut and to said inner wedge means for urging said sections away from said larger end of said outer wedge means to a rest position where said sections are laterally spaced from each other and for urging said inner wedge means toward said larger end of said outer wedge means to said rest position of said inner wedge means.

l1. An expandable assembly comprising, in combina tion, elongated outer hollow wedge means including a pair of elongated separate portions extending longitudinally of said outer Wedge means and being laterally movable with respect to each other, said outer wedge means having opposed ends one of which is smaller than the other and said pair of longitudinal portions having in the interior of said outer wedge means a pair of opposed wall portions, respectively, which converge toward the larger end of said outer wedge means; a split nut in said outer wedge means between said converging wall portions thereof and having a pair of separate sections respectively engaging lsaid wall portions so that as said sections advance toward said larger end of said wedge means said sections are pressed toward each other and engage each other; an elongated screw member extending longitudinally lalong said outer wedge means partly in the interior thereof and being accessible at the exterior of said outer `wedge means, said screw member cooperating with said split nut means for urging the same toward said larger end of said outer wedge means; inner wedge means located within and extending longitudinally along said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means having a rest position within said outer wedge means spaced from said smaller end thereof, said inner wedge means being longitudinally movable toward said smaller end of said outer wedge means for spreading said longitudinal portions thereof laterally apart from each other, said screw member cooperating with said inner wedge means lfor advancing the same toward said smaller end of said outer wedge means; spring means connected to the sections of said split nut and to said inner wedge means for urging said sections away from said larger end of said outer wedge means to a rest position where said sections are laterally spaced from each other and for urging said inner wedge means toward said 18 :larger end of said outer wedge means to said rest position of said inner wedge means; and additional spring means cooperating with said screw member for urging the same to a rest position, said screw member having threads which in said rest position of said screw member are out of engagement with said nut.

l2. An expandable assembly comprising, in combination, outer elongated hollow wedge means composed of a pair of longitudinal portions which are separate from each other and which are laterally movable away from and toward each other, said longitudinal portions being relatively distant from each other in a rest position of said outer wedge means and being movable toward each other and located relatively close to each other in an operative position of said outer wedge means, said outer wedge means having opposed ends one of which is smaller than the other; a split nut having a pair of sections respectively carried by said portions of said outer wedge means in the interior thereof and movable with said portions laterally of said outer wedge means so .that when said outer wedge means is in said rest position thereof said sections of said split nut are spaced from each other, said sections engaging each other to form a complete nut when said longitudinal portions are relatively close to each other in said operative position of said outer wedge means; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward land spaced from said smaller end of said outer wedge means and said inner wedge means having `a rest position spaced from said smaller end of said outer Wedge means and being movable along the interior thereof toward said smaller end of said outer wedge means to spread said longitudinal portions thereof apart from each other; means carried by said outer wedge means in the interior thereof for maintaining said sections of said split nut in engagement wi-th each other during longitudinal movement of said inner wedge means toward said smaller end of said outer wedge means to expand the latter; and elongated screw member accessible at the 4exterior of said outer wedge means, extending longitu- -dinally along part of the interior thereof, and cooperating Iwith said nut and said inner wedge means for advancing the latter toward said smaller end of said outer wedge means to expand said outer wedge means.

13. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable away from the interior of said outer wedge means with respect to the remainder thereof to expand said outer wedge means; elongated inner wedge means located within and extending longitudinally of said outer wedge means and having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner Wedge means having a rest position spaced from said smaller end of said outer Wedge means and being longitudinally movable in the latter toward said smaller end thereof to expand said outer Wedge means, said inner wedge means including a pair of separate longitudinal portions extending longitudinally of said outer wedge means in the interior thereof; a split nut having a pair of sections respectively fixed to said longitudinal portions of said inner wedge means and cooperating with each other to form a complete nut during longitudinal movement of said inner wedge means toward said smaller end of said outer wedge means to expand the latter; and an elongated screw member accessible at the exterior of said outer wedge means and cooperating with said nut for advancing said inner wedge means toward said smaller end of said outer-wedge means upon turning of said screw member.

, 14. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable away from the interior of said outer wedge means with respect to the remainder thereof to expand said outer wedge means; elongated inner wedge means located within and extending longitudinally of said outer Wedge means and having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means having a rest position spaced from said smaller end of said outer wedge means and being longitudinally movable in the latter toward said smaller end thereof to expand said outer wedge means, said inner Wedge means including a pair of separate longitudinal portions extending longitudinally of said outer wedge means in the interior thereof; a split nut having a pair of sections respectively xed to said longitudinal portions of said inner wedge means and cooperating with each other to form a complete nut during longitudinal movement of said inner wedge means toward said smaller end of said outer wedge means to expand the latter; an elongated screw member accessible at the exterior of said outer wedge means and cooperating with said nut for advancing said inner wedge means toward said smaller end of said outer wedge means upon turning of said screw member; and guide means carried by said outer wedge means and cooperating with said inner wedge means for guiding the latter for longitudinal movement in said outer wedge means.

15. An expandable assembly comprising, in combination, elongated outer wedge means composed of a pair of complementary longitudinal separate portions laterally movable away from each other during expansion of said outer wedge means, said outer wedge means having opposed ends one of which is smaller than the other; limiting means cooperating with said portions of said outer wedge means to limit the movement of said portions apart from each other; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said inner Wedge means having said smaller end thereof directed toward said smaller end of said outer wedge means and having a rest position spaced from said smaller end of said outer wedge means, said inner wedge means being longitudinally movable in said outer wedge means from said rest position toward said smaller end of said outer Wedge means to expand the latter; and screw means accessible at the exterior of said outer Wedge means and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand the latter.

16. An expandable assembly comprising, in combination, elongated outer wedge means composed of a pair of complementary longitudinal separate portions laterally movable away from each other during expansion of said outer wedge means, said outer wedge means having opposed ends one of which is smaller than the other; limiting means cooperating with said portions of said outer wedge means to limit the movement of said portions apart from each other, said limiting means including a pair of projections respectively carried by said portions of said outer wedge means and a ring surrounding said projections to engage the same for limiting the extent to which said longitudinal portions of said outer wedge means move apart from each other; inner wedge means located within and extending longitudinally of said outer wedge means and also having opposed ends one of which is smaller than the other, said inner wedge means having said smaller end thereof directed toward said smaller end of said outer wedge means and having a rest position spaced from said smaller end of said outer wedge means, said inner wedge means being longitudinally movable in said outer wedge means from said rest position toward said smaller end of said outer wedge means to expand the latter; and screw means accessible at the exterior of said outer wedge means and cooperating with said inner wedge means for longitudinally advancing the same from said rest position toward said smaller end of said outer wedge means to expand the latter.

17. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion which is laterally movable with respect to the remainder of said outer hollow wedge rneans away from the interior thereof during expansion of said outer wedge means, one of said ends of said outer wedge means being formed with a recess at the exterior of said outer wedge means; elongated inner wedge means located within and extending longitudinally of said hollow outer wedge means and also having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means having a rest position in said outer wedge means spaced from said smaller end thereof and being longitudinally movable toward said smaller end of said outer wedge means to engage and move said longitudinal wall portion thereof away from the interior thereof to expand said outer wedge means; and screw means cooperating with said inner wedge means `and extending longitudinally along said outer wedge means in the interior thereof for advancing said inner wedge means toward said smaller end of said outer wedge means to expand the latter, said screw means having a free end portion accessible in said recess of said outer wedge means and said free end portion terminating within said recess so that said screw means does not extend outwardly beyond said outer wedge means.

18. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including at least one longitudinal wall portion laterally movable with respect to the remainder of the outer wedge means toward and away from the interior thereof, said outer wedge means expanding during movement of said wall portion thereof away from said interior of said outer Wedge means; elongated inner wedge means located within and extending longitudinally of said outer wedge means and having also opposed ends one of which is smaller than the other, `said smaller end of said inner wedge means being directed toward said smaller end of said outer wedge means and said inner wedge means being longitudinally movable within said outer wedge means toward said smaller end thereof for laterally displacing said longitudinal wall portion away from the interior of said outer wedge means to expand the latter; tongue-and-groove means forming parts of said inner wedge means and said longitudinal wall portions of said outer wedge means to guide said inner wedge means for longitudinal movement with respect to said longitudinal wall portion of said outer wedge means; and screw means accessible at the exterior of said outer wedge means cooperating with said inner wedge means for advancing the latter toward said smaller end of said outer wedge means to laterally displace said longitudinal wall portion of said outer wedge means away from the hollow interior thereof.

19. An expandable assembly comprising, in combination, elongated hollow outer wedge means having opposed ends one of which is smaller than the other and including a pair of opposed exterior longitudinal wall portions laterally movable away from each other and away from the interior of said outer wedge means during expansion of the latter; elongated inner wedge means located within and extending longitudinally of said outer wedge means and having opposed ends one of which is smaller than the other, said smaller end of said inner wedge means being spaced from and directed toward said smaller end of said outer wedge means and said inner wedge means being longitudinally movable in said outer 21 wedge means toward said smaller end thereof to spread said longitudinal Wall portions away from each other to expand said outer Wedge means, said inner wedge means including a pair of separate longitudinal portions located directly next to said longitudinal portions of said outer Wedge mean-s; tongue-and-groove means respectively forming parts of and cooperating with said longitudinal portions of said outer and inner wedge means for guiding said longitudinal portions of `said inner Wedge means for longitudinal movement with respect to said portions of said outer wedge means; and screw means accessible at 22 the exterior of said outer Wedge ineas `and cooperating with said inner 4wedge means for advancing the latter to- Ward said smaller end of said outer wedge means to spread said longitudinal portions thereof away from each other.

Gray Aug. 18, 1931 Premo Jan. 29, 1952 

